Method of making tubular railway car axles



April 8, 1958 c. A. BRAUCHLER METHOD vOF MAKING TUBULAR RAILWAY CAR AXLES Filed 001.19, 1955 4 Sheets-Sheet l INVENTOR. 0lL-arLes.BrwzLhLer guay/f ATTORNEYS April 8, 1958 c. A. BRAucl-ILER METHOD OF' MAKING TUBULAR RAILWAY CAR AXLES Filed oct. 19, 1955 4 Sheets-Sheet 2 mm A III IIIIII IIIIIIII III II'IIIIII .v MN

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ATTRNEYS April 8, 1958 c. A. BRAUCHLER METHOD OF MAKING TUBULAR RAILWAY CAR AXLES 4 Sheets-Sheet 3 Filed Oct. 19, 1955 ATTORNEYS r mm m5. m m

METHOD F MAKlNG TUBULAR RAILWAY i CAR AXLES The invention relates to the manufacture of tubular axles for railway rolling stock, and more Vparticularly to a method of making such axles from a kbar of steel or the like.

Under present practice, it is usually customary to make the axles for railroad cars in the form of a solid bar of steel or the like. Although hollow axles are of considerably lighter weight and possess greater fatigue life and other advantages, as compared with a solid axle, relatively few tubular axles have been used in railroad equipment.

The tubular axles which have been produced for Such purpose have been usually made from seamless tubing, and are both expensive and difficult to produce. Such axles require iirst the formation of the finished `tube by rolling and piercing operations, followed by forging and upsetting operations upon opposite endsof the tube to produce the finished tubular axle.

The present invention comprises a method of forming a tubular axle from a solid bar of steel or other suitable material with a minimum of labor and expense.

lt is therefore a primary object of the invention to provide a method for economically manufacturing a tubular axle from a solid bar of metal.

Another object is to provide such a method which consists in initially forming the journal portions and wheel seats upon opposite ends of a solid steel bar by a series of upsetting, extruding and piercing operations, producing a solid axle with hollow, shaped end portions, and then cutting out the center of the solid portion to produce an axle which is hollow throughout its entire length.

A further object is to provide for a cold drawing operation to remove tool marks from the interior of the hollow axle.

A still further object is to provide a final upsetting operation to reduce the inside diameter of the journal portions of the axle.

It is also an object of the invention to provide a method of forming a tubular axle from a solid bar of steel or the like, which comprises hot forging opposite end portions of the bar by upsetting, piercing and extrusion operations to form hollow end portions with wheel seats and journal portions thereon, then cutting out the central portion of the bar as by a trepanning operation, then cold drawing the inside of the hollow product to remove tool marks, and nallyupsetting the journal portions of the axle to reduce the inside diameter thereof.

The above objects together with others which will be apparent from the drawings and following description, or which may be later referred to, may be attained by forming a tubular axle by the method hereinafter described in detail and illustrated in the accompanying drawings, and particularly pointed out in the appended claims forming a part hereof.

In general terms, the invention may be briefly described as comprising a method of forming a tubular axle from a solid bar of steel or other suitable material nite rates Patent O of cross-sectional Vsize and shape desired in the finished axle.

In carrying out the invention, opposite end portions of the bar are successively heated and subjected to a series of upsetting, piercing and extrusion operations in closed dies, to form hollow ends upon the bar, having wheel seats and journal portions formed thereon.

Then, as by a trepanning operation, an axial hole is cut through the remaining solid portion of the bar, connecting and in alignment with the hollow ends. In order to remove tool marks, the hollow inside of the partly finished product is then subjected to a cold drawing operation, as by drawing a hardened steel ball therethrough.

The axle forging is then completed by heating the journal portions and further upsetting them to reduce the inside diameter thereof, after which the wheel seats and journal portions may be ground and polished to desired dimensions.

Having thus briefly described the invention, reference is now made to the accompanying drawings showing the manner in which the method is carried out, in which:

Fig. 1 is a perspective view of a solid bar of steel or the like from which an axle may be formed by the improved method to which the invention pertains;

Fig. 2 is an enlarged fragmentary elevation, partly in section, showing the first upsetting operation upon one end of the bar;

Fig. 3 is a similar view showing the second upsetting, piercing and extrusion operation;

Fig. 4 is a similar View showing the third upsetting,

' piercing and extrusion operation;

Fig. 5 is a longitudinal sectional view through a portion of the partially completed product, showing the trepanning operation;

Fig. 6 is a longitudinal sectional view through the partially completed product, after the trepanning operation, showing the cold drawingV operation on the inside thereof;

Fig. 7 is a fragmentary sectional view of one end portion of the partially completed product, after the cold drawing operation, showing the nal upsetting operation for reducing the inside diameter of one journal portion of the axle; and

Fig. 8 is a longitudinal sectional view of the completed hollow axle forging.

Referring now more particularly to the preferred enibodiment of the invention illustrated in the drawings, in which similar reference characters refer to similar parts throughout, in carrying out the improved method of making tubular axles, a bar 10 of steel, or other suitable material, is provided. This bar is of a length approximately that desired in the nshed axle, and may be of round or other cross-sectional shape and size intended for the body portion of the axle.

Opposite end portions of the bar 19 are successively heated to forging temperature and subjected to a series of upsetting, piercing and extrusion operations, producing hollow end portions upon the bar with wheel seats and journal portions thereon.

In the first of these operations, the heated end portion of the bar is placed in a 'die 11, as shown in Fig. 2. This die has a cavity 12, of cross-sectional size and shape to receive the bar 10, and open through one end of the die, the opposite end of cavity 12 communicating axially with the enlarged cylindrical cavity 13, open through the other end of the die.

Cooperating with the die 11 is a reciprocable head 14 having a hollow cylindrical plunger 15 mounted thereon and adapted to be received in the cylindrical cavity 13 of the die 11. A central longitudinal bore 16 is formed in the plunger 15, the outer open end 17 thereof being of larger diameter than the bar 10.. The ,borev 16 is tapered.y

inwardly to the point 18,\which is of substantially the same diameter as the bar 10, and terminates in the cylindrical portion 19.` A conical piercing mandrel is located in the inner closed end of the bore 16.

ln carrying out this first step of the method, the heated end of the bar 10 is positioned in the die cavity 12-13 and the head 14 is moved toward the die 11, to the position shown in Fig. 2. The heated end portion of the bar is thus upset,` forming the tapered enlargement 21 thereon, spaced `inwardly from the cylindrical end portion 22, and forming a central conical socket 23 in the end thereof.

The tirst three steps of the method, as illustrated in Figs. 2, 3 and 4, may be carried out in rapid succession without reheating the bar between operations. For this purpose, the dies shown in these three figures, may be located side by side in a single die block, and the plungers cooperating with said dies may all be mounted upon the single head 14.

The die 24 of Fig. 3, for` performing the second step, is

provided with a cavity 25 of cross-sectional'size and shape of the bar 10, this cavity having an intermediate enlarged portion 27, tapered as at 23. The cooperating plunger 29, carried by the reciprocable head 14, has a piercing mandrel 3f! thereon, adapted to enter and pierce 1 the cylindrical outer end portion 22 of the partially completed product.

When the head 14 is moved toward the die 24, the piercing mandrel will form the central opening 31 in the end portion 22 of the bar, and this inward movement of the piercing mandrel will upset the metal into the enlarged portion 27 of the die cavity as at 32. Surplus metal will be extruded outwardly from the die cavity as indicated at 33.

The partially completed product of this operation is immediately removed from the die 24, and,.while still at forging temperature, is placed in the die 34 of Fig. 4, for performing the third step. The die cavity 35 is shaped to receive the bar 10, and is provided with the intermediate cylindrical enlargement 36 to form a wheel seat, and terminates in the reduced cylindrical portion. 37. p

A plunger 3S isxed upon the reciprocable head 14 and provided with a piercing mandrel 39 of sufficient length to extend substantially through the enlarged portion 36 of the die cavity. When the head 14 is moved inward the piercing mandrel 39 will form the central opening 40 and at the same time will upset the metal forcing it outward into the enlargement 36 of the'die cavity forming a wheel seat 41, while surplus metal will be further extruded through the open end of the die as indicated at 42.

After these three operations'have been completed upon one end of the bar 10, the other end of the bar is heated to forging temperature and the same three operations as shown in Figs. 2, 3 and 4 are performed thereon. Thus a solid bar is provided witha hollow wheel seat and journal portion at each end.

ln order to form a tubular axle, it is then necessary to cut a central opening entirely through the solid intermediate portion of the bar 10, connecting the openings 40 at each end thereof. t

For the purpose of economy in time as well as material, this may be accomplished by a trepanning operation as shown in Fig. 5. A hollow trepanning head 43, provided at its forward end with, cutters 44, is mounted upon a hollow advanceable shaft 45.

This operation may be performed cold, the trepanning head 43 being inserted through the opening40 in one end of the partially completed product, and as the bar 10 is rotated and the trepanning tool is advanced, the cutters 44 of the trepanning head will cut a cylindrical kerf 46 through the bar 10 salvaging a sizable cylindrical core 47 of the metal which may be used for some other purpose. This trepanningoperation removesv the' metal from the center of the bar which is of the greatest porosity, the more solid metal in the outer portion of the bar remaining inthe nished tubular axle.

In Fig. 6 the partially4 completed product of the trepanning operation is `shown in longitudinal section.V A hollow bar is'thus produced having the central longitudinal opening 48 extending entirely through the same with enlarged cylindrical wheel seats 41 `near opposite ends, the bar terminating ateach end in the reduced cylindrical portion 49.

In order to remove tool marks from the interior of the hollow product, a cold drawing operation may then be performed. For this purpose a hardened steel ball 50 of suitable diameter to fit within the central opening 48 of the bar, is drawn through the opening48 from one end thereof to the other, as by the rod 51 which may be rotated upon its axis as it is moved in the direction of the arrows through the opening 48.

The nal step of the method is illustrated in Fig. 7, in which a journal portion is formed upon the end of the hollow' axle. For this purpose a die 52 is provided having a cavity 53 to receive the partially completed product, the cavityv having an intermediate enlarged cylindrical portion 54 to receive the wheel seat portion 41, it being again reduced at its outer end as indicated at 55.

A plunger `56 is mounted upon a reciprocating head 57, the plunger having the flat end surface 58 and being provided with a mandrel 59 of less diameter than the central opening 48. One end of the partially completed product is heated to forging temperature and placed in the die 52 and the head 57 is operated moving the plunger 56 into the outer end portion *55 of the die cavity and inserting the mandrel 59 into the central opening 48.

The end portion of the partially completed product is thus upset forming the journal portion 60 with reduced central opening 61 andflat outer end 62. The other end of the partially completed product is then heated to forging temperature and this operation repeated producing the nished tubularaxle 10a having the enlarged cylindrical wheel seat 41 near opposite ends thereof terminating in the reduced cylindrical `journal portions 60 with flat ends 62, and having the central opening 48 extending entirely therethrough and of reduced diameter within the journal portions 60 as indicated at 61.

The hollow axle forging as shown in Fig. 8, may then be heated, quenched and tempered to the proper hardness, may be shot-peaned to increase the physical strength, and, when cooled, is ready for the linal nish on the journal portions and wheel seats. A tubular axle produced in this mannerhas many advantages over the conventional solid axle and also over such hollow axles as have been made in the past from seamless tubes.

As compared with the solid axle, this tubular axle is considerably lighter in weight, thus materially reducing the weight of a railroad car equipped with the same, as

' well'as providing less weight to khandle in plant operations. The tubular axle has greater strength and fatigue life than a solid axle, and thus the factor of safety is higher.

The solid bar blank used in the manufacture of the hollow axle is economical in comparison to the seamless tube, because of minimum operations in the steel mill. The hot working of the bar to form the wheel seats and journals improves the physical structure.

In the foregoing description, certain terms have been used for brevity, clearness and understanding, but no unnecessary limitations are to he implied therefrom beyond ,the requirements of the prior art, because such words are used for descriptive purposes herein and are intended to be broadly construed. t

Moreover, the embodiments of the improved method illustrated and described herein are by way of example, and the scope of the present invention is not limited to the exact details of construction.

Having now described the invention or discovery, the method, the operation, and use of preferred embodiments matinalv thereof, and the advantageous new and useful results obtained thereby; the new and useful method steps, and reasonable equivalents thereof obvious to those skilled in the art, are set forth in the appended claims.

I claim:

1. The method of making a tubular axle which consists in providing a solid bar of proper length to form an axle and of substantially the cross-sectional size and shape desired in the greater portion of the length of the nished axle, heating the end portions of the bar to forging temperature, forging the hot lend portions of the bar in closed dies to produce tapered enlargements of larger diameter than desired in the wheel seats of the finished axle spaced from the ends of the bar, further forging said hot end portions of the oar to upset said'tapered enlargements and simultaneously piercing openings in the ends of the bar to the youter ends of said tapered enlargements and extruding the ends of the bar, further forging said hot Vend portions to further upset and reduce the diameter of said tapered enlargements to produce cylindrical wheel seats and simultaneously piercing said openings in the end portions of the bar through said wheel seats and further extruding the ends yof the bar, then in a single trepanning operation cutting a longitudinal opening through the solid bar communicating with the pierced end portions thereof, again heating the end portions of the bar to forging temperature and forging the hot end portions of the bar to upset the portions thereof beyond said wheel seats and reduce the diameter of the outer ends of the piercedopenings therein to produce journals at the ends of the bar.

2. The method of making a tubular axle which consists in providing a solid bar of proper length to form an axle and of substantially the cross-sectional size and shape desired in the greater portion of the length of the nished axle, heating the end portions of the bar to forging temperature, forging the hot end portions of the bar in closed dies to produce tapered enlargements of larger diameter than desired in the wheel seats of the finished axle spaced from the ends of the bar, further forging said hot end portions of the bar to upset said tapered enlargements and simultaneously piercing openings in the ends of the bar to the outer ends of said tapered enlargements and extruding the ends of the bar, further forging said hot end portions to further upset and reduce the diameter of said tapered enlargements to produce cylindrical wheel seats and simultaneously piercing said openings in the end portions of the bar through said Wheel seats and further extruding the ends of the bar, then in a single trepanning operation cutting a longitudinal opening through the solid bar communicating with the pierced end portions thereof, then cold drawing the interior of the hollow bar by drawing a steel ball therethrough and rotating the ball around the longitudinal axis of the bar to remove tool marks, again heating the end portions of the bar to forging temperature and forging the hot end portions of the bar to upsetthe portions thereof beyond said wheel seats and reduce the diameter of the outer ends of the pierced openings therein to produce journals at the ends of the bar.

3. The method of making a tubular axle which consists in providing a solid bar of proper length Ito form an axle and of substantially the cross-sectiona1 size and shape desired in the greater portion of the length of the finished axle, heating the end portions of the bar to forging temperature, forging the hot end portions of the bar in closed dies to produce tapered enlargements of larger diameter than desired in the wheel seats of the finished axle spaced from the ends of the bar, further forging said hot end portions of the bar to upset said tapered enlargements and simultaneously piercing openings in the ends of the bar to the outer ends of said tapered enlargements and extruding the ends of the bar, further forging said hot end portions to further upset and reduce the diameter of said tapered enlargements to produce cylindrical wheel seats and simultaneously piercing said openings in the end portions of the bar through said wheel seats and further extruding the ends of the bar, then in a single trepanning operation cutting a longitudinal opening through the solid bar communicating with the pierced end portions thereof, again heating the end portions of the bar to forging temperature and forging the hot end portions of the bar to upset the portions thereof beyond said wheel seats and reduce the diameter of the outer ends of the pierced openings therein to produce journals at the ends of the bar, then heating, quenching and tempering the hollow axle forging to proper hardness.

References Cited inthe file of this patent UNITED STATES PATENTS 9,961 Walbach Aug. 23, 1853 761,778 Mercader June 7, 1904 `1,177,983 Avis Apr. 4, 1916 1,402,508 Lothrop Jan. 3, 1922 1,845,122 Briney Feb. 16, 1932 2,256,065 Urschel et al Sept. 16, 1941 2,610,529 Atkinson Sept. 16, 1952 

